1. $Fe_2(SO_4)_3+6NaOH\to 2Fe(OH)_3+3Na_2SO_4$
$2Fe^{3+}+3SO_4^{2-}+6Na^++6OH^-\to 2Fe(OH)_3+6Na^++3SO_4^{2-}$
$\to Fe^{3+}+3OH^-\to Fe(OH)_3$
2. Không phản ứng
3. $Cu(OH)_2+2HCl\to CuCl_2+2H_2O$
$Cu(OH)_2+2H^++2Cl^-\to Cu^{2+}+2Cl^-+2H_2O$
$\to Cu(OH)_2+2H^+\to Cu^{2+}+2H_2O$
4. $Zn(OH)_2+2NaOH\to Na_2ZnO_2+2H_2O$
$Zn(OH)_2+2Na^++2OH^-\to 2Na^++ZnO_2^{2-}+2H_2O$
$\to Zn(OH)_2+2OH^-\to ZnO_2^{2-}+2H_2O$
5. Không phản ứng
6. $K_2CO_3+Ba(NO_3)_2\to BaCO_3+2KNO_3$
$2K^++CO_3^{2-}+Ba^{2+}+2NO_3^-\to BaCO_3+2K^++2NO_3^-$
$\to Ba^{2+}+CO_3^{2-}\to BaCO_3$
7. $FeS+2HCl\to FeCl_2+H_2S$
$FeS+2H^++2Cl^-\to Fe^{2+}+2Cl^-+H_2S$
$\to FeS+2H^+\to Fe^{2+}+H_2S$
8. $CuSO_4+2NaOH\to Cu(OH)_2+2Na_2SO_4$
$Cu^{2+}+SO_4^{2-}+2Na^++OH^-\to Cu(OH)_2+2Na^++SO_4^{2-}$
$\to Cu^{2+}+2OH^-\to Cu(OH)_2$
9. Không phản ứng
10. $CaCO_3+2HCl\to CaCl_2+CO_2+H_2O$
$CaCO_3+2H^++2Cl^-\to Ca^{2+}+2Cl^-+CO_2+H_2O$
$\to CaCO_3+2H^+\to Ca^{2+}+CO_2+H_2O$
11. Không phản ứng
12. $AgNO_3+KCl\to AgCl+KNO_3$
$Ag^++NO_3^-+K^++Cl^-\to AgCl+K^++NO_3^-$
$\to Ag^++Cl^-\to AgCl$
